How people make friends in social networking sites - A microscopic perspective

TL;DR

This paper investigates the microscopic processes of friendship formation on social networking sites, revealing detailed temporal behaviors and preferences that shape the macroscopic network structure.

Contribution

It provides a comprehensive analysis of user interaction dynamics and introduces a network model based on linear preferential linking to explain the observed degree distribution.

Findings

Reciprocation intervals decay exponentially.

User behavior intervals follow a power law with a universal exponent.

Linear preferential attachment explains network degree distribution.

Abstract

We study the detailed growth of a social networking site with full temporal information by examining the creation process of each friendship relation that can collectively lead to the macroscopic properties of the network. We first study the reciprocal behavior of users, and find that link requests are quickly responded to and that the distribution of reciprocation intervals decays in an exponential form. The degrees of inviters/accepters are slightly negatively correlative with reciprocation time. In addition, the temporal feature of the online community shows that the distributions of intervals of user behaviors, such as sending or accepting link requests, follow a power law with a universal exponent, and peaks emerge for intervals of an integral day. We finally study the preferential selection and linking phenomena of the social networking site and find that, for the former, a linear preference holds for preferential sending and reception, and for the latter, a linear preference also holds for preferential acceptance, creation, and attachment. Based on the linearly preferential linking, we put forward an analyzable network model which can reproduce the degree distribution of the network. The research framework presented in the paper could provide a potential insight into how the micro-motives of users lead to the global structure of online social networks.